Blog

When to plant Nasturtium in Jasper County, IL

Plant Nasturtium in Jasper County after April 13; the prime window is April 13–May 4.

When to Plant Nasturtium in Jasper County, IL

Jasper County, Illinois Zone 6b June

Your June game plan for Jasper County, Illinois

Your Jasper County, Illinois garden is entering a new phase. Here's what's on the schedule for June and why each task matters now.

Avg. last frost April 13
Avg. first frost October 20
Soil temp (4") 73°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Harvest nasturtium as they ripen

    Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.

Coming up in July — start thinking about
  • First harvests: nasturtium

Instant PDF download. No spam, unsubscribe any time.

Nasturtium (Tropaeolum majus) is a fast-growing annual with distinctive round, lily-pad leaves and bold trumpet-shaped blooms in warm oranges, reds, and yellows. Both the flowers and leaves are edible with a peppery watercress flavor. Planted near vegetables, nasturtiums act as a sacrifice trap-crop, luring aphids away from more valuable plants. They thrive in poor, dry soil — rich conditions produce lush foliage but few flowers.

Jasper County, Illinois is in USDA Zone 6b. The average last spring frost is April 13 and the first fall frost is October 20, giving you a growing season of approximately 190 days.

At an elevation of 1,384 feet, Jasper County receives approximately 35 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Nasturtium during the growing season.

Annual Blooms in Multi-season Pollinator-friendly Deer-resistant Good for cutting Fragrant
Jasper County, IL (Zone 6b) Moderate season
190 days
Last Spring Frost April 13
190 growing days
First Fall Frost October 20

Jasper County Soil Profile

Soil Type

Silt Loam

Soil pH

5.9-7.3

Drainage

Well Drained

Nasturtium Planting Risk Windows

Early Start (70% safe) ✓ Fits season (15 days to spare)
Start indoors: Mar 10 Transplant: Apr 7 🌸 Bloom: Jun 2 – Sep 29
Recommended (50%) ✓ Fits season (15 days to spare)
Start indoors: Mar 16 Transplant: Apr 13 🌸 Bloom: Jun 8 – Oct 5
Safe Start (90%) ✓ Fits season (12 days to spare)
Start indoors: Mar 30 Transplant: Apr 27 🌸 Bloom: Jun 22 – Oct 19

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Jasper County

How your county's soil matches Nasturtium's growing requirements.

Soil pH

Your soil pH (5.9–7.3) overlaps with Nasturtium's range (6.0–8.0), though not a perfect match.

Soil Texture

The silt loam soil in Jasper County is excellent for Nasturtium — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.5%) — Nasturtium will thrive.

How to Plant Nasturtium

0.5"
Planting Depth
10"
Between Plants
12"
Between Rows

Succession Planting Nasturtium

4
successive plantings in your 190-day season

Sow every 6.3 weeks. Last sowing by Aug 16 to harvest before frost.

Nasturtium Water Budget

Plant needs
0.5″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Nasturtium

Nasturtium needs approximately 0.5 inches of water per week (2.2" per month). Here's how your county's rainfall compares month by month.

Month Nasturtium Needs Rainfall You Supplement Action
Jan 1.4" 0" ❄️ Dormant
Feb 1.5" 0" ❄️ Dormant
Mar 2.4" 0" ❄️ Dormant
Apr 2.2" 3.1" 0" ✅ Rainfall sufficient
May 2.2" 4.1" 0" ✅ Rainfall sufficient
Jun 2.2" 4.7" 0" ✅ Rainfall sufficient
Jul 2.2" 3.3" 0" ✅ Rainfall sufficient
Aug 2.2" 3.5" 0" ✅ Rainfall sufficient
Sep 2.2" 3.4" 0" ✅ Rainfall sufficient
Oct 2.2" 3" 0" ✅ Rainfall sufficient
Nov 2.5" 0" ❄️ Dormant
Dec 2.2" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Jasper County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Nasturtium Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Nasturtium needs ~1,095 GDD — county provides 3,467 GDD Excellent fit

Nasturtium Planting Timeline — Jasper County, IL

Nasturtium Planting Calendar

Activity When Date Range
Start Indoors March 16 Mar 16 – Mar 30
Transplant Outdoors April 13 Apr 13 – Apr 27
Direct Sow April 13 Apr 13 – May 4
Bloom June 8 Jun 8 – Oct 5

Plant 0.5" deep · 10" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Transplant Outdoors Direct Sow
May Direct Sow
June Bloom
July Bloom
August Bloom
September Bloom
October Bloom
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.5"/week · Natural rainfall sufficient

📅 Days to Maturity

55–65 days

🧪 Soil pH

Needs 6–8 · Your soil: acceptable

🗺️ USDA Zone

Zone 6b

📆 Growing Season

190 days in Jasper County

Growing Tips for Nasturtium in Jasper County

Direct sow Nasturtium outdoors after April 13 in Jasper County when soil has warmed and frost danger has passed.

General growing tips

Direct-sow large seeds 1/2 inch deep after last frost; soak seeds overnight to speed germination (7-10 days). Nasturtiums dislike root disturbance so direct sowing is strongly preferred. Avoid fertilizing — poor soil brings the best bloom. Trailing types can cover banks and climb trellises; dwarf types suit containers. In hot climates (zones 9+) plant in fall for winter/spring bloom as plants struggle in peak summer heat.

Companion Planting

Good Companions

Avoid Planting Near

  • Fennel

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Nasturtium in Jasper County, IL?

Jasper County is in Zone 6b with an average last frost of April 13. Plan your Nasturtium planting based on this frost date — see the calendar above for exact timing.

What planting zone is Jasper County, IL?

Jasper County, Illinois is in USDA Hardiness Zone 6b. The average last spring frost is April 13 and first fall frost is October 20.

When should I plant Nasturtium in Jasper County, IL?

In Jasper County, IL, plant Nasturtium after the last frost (around April 13) and before the first frost (around October 20). Best results when soil holds above 50°F.

What growing zone is Jasper County, IL for Nasturtium?

Jasper County sits in USDA Zone 6b. Nasturtium grows reliably in zones 2a through 11b, so it's a good fit here.

Can Nasturtium grow in Jasper County's climate?

Yes — Nasturtium grows well in Jasper County's temperate climate. Jasper County averages a 190-day frost-free season, with last frost around April 13 and first frost around October 20.

🌱

Your Jasper County Garden Planner — Free

A 22-page printable planner built for Jasper County (Zone 6b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Jasper County, IL. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.